Positive cabinet lock



Dec. 26, 1961 D. w. CRAIK 3,014,744

POSITIVE CABINET LOCK Filed Jan. 20, 1959 2 Sheets-Sheet 1 Dec. 26, 1961D. W. cRAlK POSITIVE CABINET LOCK 2 Sheets-Sheet 2 Filed Jan. 20, 1959 Rm E V W .Il lilllill\lllllllli\\ iinited States @arent @ffice lijidPatented Dec. 26, il

3,014,744 PSlTlVE CABENET LUCK Darrel W. Qrailk, 6532 N. Hickory,Escondido, Calif. Filed dan. 20, 1959, Ser. No.. 77,966

2 Claims. ttCl. 292--l7} ll`his invention relates to locks or catchesfor cabinet doors or other closures.

Cabinet doors in moving vehicles, such as trailers, airplanes, boats andthe like, often fly open unless special locking devices are employed.Releases for cabinets out of the reach of children may also be desiredso that a pull at the lower edge of the cabinet is ineitective to openthe cabinet. For various other reasons, positive locks are oftendesirable.

Known positive locking devices have serious drawbacks. Usually theyrequire manipulations in addition to the simple pull or push at a doorpull; if not unsightly, such known devices are expensive or complex.

The primary object of this invention is to provide an improved positivelock for a cabinet door or the like that is simple and inexpensive.

Another' obiect of this invention is to provide an improved positivelock for a cabinet door or the like in which the lock is released by thevery action of pulling the door pull and in which the lock is setautomatically by closure of the door or the like.

Still another object of this invention is to provide a positive lock theoperative parts of which are virtually concealed. This, together withthe single manipulation feature, makes the user actually unaware of thefact that a positive lock is operative.

Yet another object of this invention is to provide a positive lock ofthis character that is easily and efficiently installed.

Yet another object of this invention is to provide a new positive lockwhich requires for installation no alterations of the cabinet structureexcept the provision of a simple through bore in one of the cabinetstructure parts.

This invention possesses many other advantages, and has other objectswhich may be made more clearly apparent from a consideration of severalembodiments of the invention. For this purpose, there are shown a fewforms in the drawings accompanying and forming part of the presentspecification. These forms will now be described in detail, illustratingthe general principles of the invention; but it is to be understood thatthis detailed description is not to be taken in a limiting sense, sincethe scope of the invention is best dened by the appended claims.

Referring to the drawings:

FIGURE 1 illustrates a typical cabinet structure incorporating thepresent invention;

FIG. 2 is an enlarged fragmentary sectional view, taken along the planeindicated by line 2.--2 of FIG. l, and illustrating the lock structureset in locking position and the corresponding cupboard door closed;

FIG. 3 is an enlarged fragmentary sectional view,

taken along the plane indicated by line 3 3 of PEG. 2;

FIG. 4 is a View similar' to FIG. 2, but illustrating the lock releasedimmediately prior to opening of the cabinet door; i

PEG. 5 is a View similar to FiGS. 2 and 4, but iliustrating the partsafter opening movement of the cabinet door;

FIG. 6 is a fragmentary view illustrating a moditied form of the presentinvention; and

FIG. 7 is a longitudinal sectional view, taken along the plane indicatedbyline 7-7 of FiG. 6.

ln PEG. l, there is iliustrated a cabinet structure it? having doors l2and 16 and an intermediate shelf TA. The doors l2 and lo are hingedrespectively at the left 2 and right so that tieir outer edges meet atthe center when the doors are closed. A lock structure is provided foreach door. The shelf i4 serves conveniently and conventionally as asupport for one of the two elements of each lock structure.

ri`he details of the lock structure are shown clearly in FIG. 2. A ballhead screw l of resilient material is mounted upon the support or shelf1d so that its ball end 2t) projects forwardly of the vertical surface1S.

The ball 2@ forms a strike that is releasably held by a keeper or catch22 mounted upon the door or ciosure i2. The catch 22 is formed as a`generally hollow body, having a recess 23 extending inwardly from oneend. The catch is accommodated in a through bore 2li of the cabinet doorl2 with its recess 23 facing inwardly. Several exterior thread turns, asat 26, are formed at the outer end of the catch ZZ for engagement withthe bore 24, whereby the catch is attached to the door i2 withoutrequiring the catch Z2 to project inwardly beyond the bore 24. Thethreads have a larger external diameter than the bore 24.

For installation of the catch 22, the end remote from the thread turnsis placed in the bore 2.1i until the inner end thread turn engages theedge at the outer side of the door l2. Rotation of the catch 22 nowcauses the thread turns to form their own channel in the bore 2li of thedoor i2.

A head 28, adjoining the outer end thread turn, serves as a means forrotating the catch 2?., and as a means for limiting inward movementthereof.

Frictional engagement between the head 28 and the edges about the end ofthe bore Z4 when the catch is fully inserted restrains angular movementot the catch ZZ.

The head 2S has a diametric slot whereby it may be engaged by ascrewdriver or the like.

The head 2&3 is longitudinally slotted to impart flex-A ibility so thatit may be resiliently contracted. It enters the right-hand end of thecatch 22. and passes through an opening 3i? that is restricted relativeto the head 20 to an area less restricted. Accordingly, the resilienceof the head 2d, which resists constriction, causes it to be held at theless restricted area. In the present instance, the relatively restrictedlopening and the area of less restriction are provided by a sphericalseat 32 in the form of an equatorial Zone that is formed inwardly of theend of the catch bore 2li.

In the present instance, two intersecting slots 3d and 36 divide thehead 2t) into quadrants or sections to provide the necessary resilientcontraction to pass the restricted opening 3b. When it passes therestricted opening 3d, the head 2t) springs outwardly in order toconform substantially to the spherical seat 32. Desirably the size ofthe spherical seat 32 is slightly less than the normal size of the head29. Accordingly, there is a firm. frictional engagement between theparts, and rattles are prevented.

The axial spacing of the head Ztl from the end surface 1S can beadjusted to compensate for the thickness of the door .i2 so that thedoor is closed when the head 2t? engages the seat 32. lf the door l2 isactually thinner than the length of the catch 22, a counterbore at theshelf may be provided.

To open the door i2, the catch 22 must be separated from the screwstrike i8. In order for this to be possible, the head Ztl must beconstrieted for passage through the restricted opening Sil. A lockingprojection or pin 3S normally prevents the constriction of the head 24Bso that, until withdrawn, it is impossible to separate the catch 22 vand the strike i8.

A recess 42 is formed centrally of the head 20 (see also FG. 3) prior tothe provision of the slots 34- and 356; the recess has a diametergreater than the Width of 3 the slots so that arcs in the inner cornersof the quadrant fingers remain. The pin 3S projects into this recess,and ts the four arcs, in order to prevent constriction of the head 20whenever the pin is in position.

The pin 33 is formed at the end of a plunger that is guided for movementlongitudinally in the catch bore recess 23.

The plunger 4G has a reduced stem at that end opposite the pin Theplunger passes outwardly through an aperture at the bottom of tho catchbore recess 23, and beyond the catch head A coil spring 52 surrounds thestem 44 in the recess 23 and urges the plunger do toward the inner endof the body L12, and the pin 3S in a direction corre pending to lockingrelationship with the screw head 20. The bottom Sil of the body recess23 forms a seat for the spring L12. The limit of inward movement of theplunger' in locked position is determined by engagement of the endsurface S6 of the plunger, from which the pin 313 projects, with the endsurfaces of the quadrants of the strike head7 as illustrated in FIG. 2.

`The plunger #itl must be retracted against the force ot the spring inorder to unlock the catch. A doc-r pull 4 formsthe lock operatingmember. In' this instance, 'the pull is in the form of a knob mountedupon the projecting end of the plunger 4t?. The knob 54 has a centralrecess 56 in its base in which thc end of the plunger 40 is received. Aset serieul 58, mounted by the base of the knob 54, engages in anannular groove 60 adjacent the end of the plunger 45 to hold the partstogetler. The knob base 55, by engagement with the head 23, limitsmovement of the plunger 40 under thc inuence of the spring S2 when thecatch and strike 'are separated, and prevents separating movement of theplunger fi-0 from the catch body. By pulling the knob 54 outwardly in adirection corresponding to the separating movement of the door l?. andas illustrated in FIG. 4, the pin 38 clears the head recess before thedoor l2 moves. A continued pull 'Urpn the knob 54 causes the catch 22 toseparate from the strike head 2G, as illustrated in FlG. 5.

The force necessary to release the pin 38 is quite slight, especially incomparison to the force necessary to cause constriction of the ball endof the strike 18. The user actually does not recognize that his pull iseffective in two steps to accomplish the two functions in sequence.

To cause the lock to be operative, it is only necessary to close thedoor by any means, such as by a push anywhere on the door. It isunnecessary to manipulate the knob 54. The strike head 29 is partiallyconstricted and has partially entered the restricted opening 30 beforethe pin is engaged. It is vital that this be the case; otherwise,necessary further constriction of the head would be precluded, and thelock would jam. Advance constriction of the head accomplishes thisresult, for now the opening 42 is restricted and the pin 38 cannotenter. Accordingly, the pin 3S and plunger 40 are pushed in advance ofthe head 20 until the recess 4.2 enlarges sufciently to permit the pinto enter therein. This occurs only when the head 20 expands to engagethe seat 32. Accordingly, locking occurs automatically after the catchand strike are engaged.

ln FIGS. 6 and 7, there is illustrated an alternate door pullarrangement utilizing a handle 7G. The handle has one end alixed to thedoor, as by a screw 72. The other end of the handle has a bifurcated end74 which fits within the annular groove oil of the plunger stem 454. Torelease the lock, two or three vlingers enter behind the i andle and anoutward pull causes the pin first to be removed from locking position,and then the catch and door move in unison away from the strike.

ln any event, the positive lock structure is inconspicuous. lt issubstantially hidden behind the door pull 54 in the form illustrated inFlGS. 1 to 5 or the handle 7) in the form illustrated in FIGS. 6 and 7.The door pull attached to the plunger 40 lies about as close to the doorproper as a conventional pull. These factors, plus the virtual singlemanipulation, combine to produce an effective positive lock of which theuser is unaware. The installation of the catch body Z2 is no morediicult than the installation of a conventional door pull; since thepresent structure substitutes for the usual door'pull, no additionalinstallation time is required.

Of course, vibrations and other forces exerted upon the door 12 will notbe effective to retract the pin 33; hence, the door cannot be openedexcept by pulling the knob 54. It is possible to utilize this device ina cabinet the doors of which are hinged on non-vertical axes, or onclosures guided for other than horizontal movement.

The inventor claims:

1. In a positive lock structure: a hollow body adapted to project into athrough bore in a first cabinet structure, and having an inner end andan outer end; said hollow body having screw-threaded provisions forattachment to a through bore in the cabinet structure, including a headat the outer end providing a shoulder for engaging the edges about thebore; said body having a substantially cylindrical recess extending fromthe inner end of the body, and an aperture extending through the bottomof the recess at the outer end of the body; the body having an interiorgroove adjacent the inner end thereof; a round-head screw of resilientmaterial adapted to be mounted on a second cabinet part, the head of thescrew being slotted to impart flexibility to head sections thus formed;the screw head being entrance into the recess at the inner end of saidbody for cooperation with said interior groove; a plunger guided by thebody in the recess, and having a stem projecting through said aperture;said plunger having a projection capable of entrance between the screwhead sections to prevent exure thereof adequate to permit disengagementfrom said body; a coil spring in the bottom of the body recess andurging the plunger toward the inner end of the body; and a lockoperating member detachably affixed to the outer end of the stem andengageable with the body head to prevent separating movement of theplunger from the body.

2. The combination as set forth in claim l, in which said attachmentprovisions of the body comprise peripherally formed wood screw threadsadjacent the body head, whereby the inner end of the body need notproject beyond the edge of the cabinet Structure.

References Cited in the le of this patent UNITED STATES PATENTS 289,666Lee Dec. 4, 1883 661,460 Tefft et al. Nov. 6, 1900 861,526 Little July30, 1907 1,300,579 Carr Apr. 15, 1919 1,647,780 Carr Nov. 1, 19271,866,326 Stevens July 5, 1932 2,480,662 Mclinzie Aug. 30, 19492,807,489 Adams Sept. 24, 1957 FORETGN PATENTS 677,438 Germany June 26,1939 capable by flexure of-

